<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.bootcdn.net/ajax/libs/vue/2.6.14/vue.js"></script>
</head>
<body>
        <div id="app">
            <son ref="sonRef"></son>
        </div>
</body>
<script>
    Vue.component('son',{
        data(){
            return{
                money:0
            }
        },
        template:`
        <div>
                <h3>子组件-{{money}}</h3>
                <button @click="handleClick">cost</button>
            </div>
        `,
        methods: {
            handleClick(){
                this.money-=100
            }
        },
    })
    new Vue({
        data(){
            return{

            }
        },
        mounted() {
            this.$refs.sonRef.money = 1000
        },
        el:"#app"
    })
</script>
</html>